A great many cameras are made with the shape of the film, during exposure, determined by the fit of a back cover to a frame. The frame has an exposure frame or intermediate section including an exposure opening, positioned in front of a film segment. The back cover has a platen backing up the film segment. In production, the curvature or flatness of the film plane between the intermediate section and platen is determined by the combined dimensions of the respective parts and tolerances, and by additional tolerances due to attachment of the two parts. This is not a particular problem in more expensive cameras, since a spring loaded platen can be used to minimize the actual size of the film path during use. It is a problem in conventional one-time use cameras, in which the platen is a fixed protrusion of the back cover and the back cover is inexpensively attached.
It would thus be desirable to provide an improved camera frame assembly in which the film plane is not created by joining one part having an intermediate section to a second piece having a platen.